Abstract
Additive manufacturing can be used to create complex optimal structures through topology optimization. However, the overhang constraint, which requires costly support materials, is a problem when part of the structure is unsupported. Previously, the fictitious physical model was proposed to consider geometric manufacturing requirements, e.g., the overhang constraint. However, converging to a single optimal structure is challenging in the fictitious physical model because the model acts noninteractively as the mechanical model describing physical phenomena. To solve the convergence problem, we propose a coupled fictitious physical model, where two models interact by changing the material constants of the mechanical model in regions where geometric constraints defined in the fictitious physical model are violated such that the objective function worsens. In this paper, the proposed model is formulated based on the steady-state heat conduction problem with overhang constraint. Then, the optimization problem and sensitivity analysis are discussed. Finally, the proposed model is verified using an example two-dimensional heat conduction problem.